2008Chapter4post

2008Chapter4post - Chapter 4 Cell Structure and Function...

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Unformatted text preview: Chapter 4 Cell Structure and Function Scientists are creating "new" organisms by removing genes from living cells. What are the advantages and bioethical pitfalls to this kind of research? http://bioethics.net Cell Theory 1. All living things are made up of one or more ________. 2. The cell is smallest unit having properties of ________. 3. All cells come from pre-______ cells by division. 4. Cells contain _________ information which is passed from cell to cell during division. 5. All cells are basically the same in ________ composition. 6. All _____ flow (metabolism & biochemistry) of life occurs within cells. Overview of Cells All cells have - plasma membrane - DNA - cytoplasm Plasma Membrane Defines the cell as a distinct entity Fig. 4-4, p.52 Lipid bilayer = __ layers of phospholipid molecules Fluid Mosaic Model "Fluid" properties from phospho_______ "Mosaic" of Phospholipids ____ lipids Sterols ______: adhesion, communication, recognition, receptor Most phospholipids and some proteins can __________ through membrane Plasma Membrane extracellular environment Recognition protein Receptor protein lipid bilayer cytoplasm Protein pump across bilayer Protein channel across bilayer Protein pump Fig. 4-5a, p.53 Why Are Cells So Small? Surface-to-volume ratio The bigger a cell is, the _____ surface area there is per unit volume Above a certain size, material cannot be ________ in or out of cell fast enough Consider a spherical cell (r = radius) Surface area = 4 r2 Volume = (4 r3 ) / 3 If cells grows 4 times wider Volume increases by _____ Surface area increases by _____ Each unit of cell membrane must serve 4 times amount of cytoplasm _________ has limits! Surface-to-Volume Ratio Prokaryotic Cell Structure Archaea and Eubacteria bacterial flagellum plasma membrane pilus bacterial flagellum most have a cell wall and many have a jellylike capsule cytoplasm, with ribosomes DNA in nucleoid region Adaptations of Archaea Proteins anchored to membrane surface Can withstand extreme ____________ Fig. 4-12b, p.57 Eukaryotic Cells Common eukaryotic organelles Refer to Fig. 4.15 Table 4.2 Typical Components of Cells Structure Cell wall Plasma membrane Nucleus Bacteria Protist Fungi Plant Animal Nuclear Envelope - 2 bilayers (_ phospholipid molecules) Nuclear envelope Nucleolus Dense mass of DNA & _________ May be one or more in nucleus Contain materials from which ________ subunits are built Table 4.2 Typical Components of Cells Structure Ribosome Protein synthesis Bacteria Protist Fungi Plant Animal Endoplasmic Reticulum Protein modification Golgi body Final processing lipids, proteins Endoplasmic Reticulum (ER) Continuous with nuclear envelope Rough ER Flattened sacs with _______ on surface Polypeptide chains enter and are ________ Cells that specialize in ________ proteins have lots of rough ER Smooth ER Interconnected tubules ___ ribosomes Lipids assembled inside Smooth ER of liver inactivates wastes, _______ In testes synthesize testosterone Sarcoplasmic reticulum of _______ is a specialized form Golgi Bodies Finishing touches on ______ and lipids that arrive from ER Package material for shipment Material arrives and leaves in _________ Vesicles = membranous sacs Lysosomes Intracellular digestion (_________) Need vitamin ___ to function 30 inherited metabolic disorders involving lysosomes (usually faulty __________) Peroxisomes Enzymes to break down fatty acids, amino acids and ________ peroxide, and alcohol The endomembrane system refer to Fig. 4.18 Table 4.2 Typical Components of Cells Structure Lysosome Intracellular digestion Bacteria Protist Fungi Plant Animal Mitochondrion ATP formation Chloroplasts Photosynthesis * Found in some groups Mitochondria ______ -production Double-membrane system Inner membrane folds Each fold = _______ Inner mitochondrial membrane Outer mitochondrial membrane Form inner and outer compartments Fig. 4-19b, p.64 Chloroplasts: convert sunlight energy into ATP through photosynthesis Thylakoid membrane, a muchfolded single flattened compartment inside the stroma stroma (semifluid interior) ____ outer membranes Fig. 4-20, p.65 Endosymbiotic Theory Mitochondria and chloroplasts resemble __________ Have own DNA, _____, and ribosomes One cell may have _______ another but not digested it... Fig. 20.11 Endosymbiotic Theory http://faculty.ircc.edu/faculty/tfischer/images/endosymbiosis.jpg Cytoskeleton Present in all __________ cells Cell shape and _______ organization Organelle movement within cells and cell motility Microtubules, microfilaments and intermediate filaments Microtubules Largest Composed of protein ________ From microtubule organizing centers (MTOCs) Polar and dynamic Involved in shape, motility, cell division Fig. 4.25 Microfilaments Thinnest Composed of protein _______ Polar and dynamic cell shape Fig. 4-25a,b, p.69 Movement, formation and maintenance of Intermediate Filaments Present only in animal cells & certain tissues (used to identify ______ cells) Most stable Examples: desmins (hold contractile filaments together) lamins (reinforce nucleus) Fig. 4-25c, p.69 tubulin subunits one polypeptide chain 5-7 nm 8-12 nm actin subunit Fig. 4-24, p.68 Kinesin and dynein = ________ proteins Move along microtubules Motor proteins Cilia and Flagella - structure = 9 + 2 array of __________ Refer to Fig. 4.29 False Feet (Pseudopods) Free-living cells (amoebas) Locomotion and _____ capture Mechanism: microfilaments elongate Fig. 4-28b,c, p.70 ______ proteins attached to microfilaments drag plasma membrane Review Questions Chapter 4 Pages 72-73 - Self-Quiz #1-7 - Critical Thinking #1-3 Question 3 Kartagener syndrome Fig. 4-30, p.73 ...
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This note was uploaded on 09/25/2008 for the course BIOL 119 taught by Professor Muma during the Spring '08 term at Ithaca College.

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